September. Improvements to the island and lake continued: The Corps spent $55,000 for a rock and concrete riprap wall around Kingman Lake, and another $20,000 for gates and conduits at the north and south ends of the lake to maintain a constant water level in lake. The Corps wanted to install a lock in the southern end of the lake to give pleasure boats access to it, and began laying plans for a second lake (East Lake) on the eastern side of the Anacostia River opposite Kingman Lake. That same year, the National Aeronautic Association proposed filling in all or part of Kingman Lake to build a new city airport. In early 1929, a channel deep was dredged under Benning Bridge as it passed over Kingman Lake. (As of 1998, due to the reconstruction of Benning Bridge and other changes, this had been replaced with a wide culvert.) The dredging ship Benning also dredged about half of Kingman Lake to deepen it. By this time, the conduit and gates had been installed in the lake's lower exit, and the upper gates were expected to be installed soon. About of the western shore of Kingman Lake between Gallinger Hospital and Benning Bridge were set aside for gardens in March 1933 to provide food for the needy. The drainage of raw sewage into Kingman Lake and the Anacostia River first became an issue in the early 1930s. An open sewer channel drained into Kingman Lake through the middle of this tract, but a footbridge was constructed over it to link the two areas. Later that year, the Army Corps of Engineers spent $853,000 to extend Washington's sewer system to Bladensburg to collect raw sewage being dumped into the Anacostia River and Kingman Lake. In 1934, the Corps of Engineers transferred ownership of the Anacostia Flats and Kingman Lake to the National Park Service. As the Corps continued to dredge fill, it expanded the flats on the eastern side of Kingman Lake, making it smaller than originally intended. Work on the lake stopped in 1941 due to budgetary and resource shortages associated with the advent of World War II. Health issues regarding Kingman Lake again became prominent in the mid-1950s. An American University biologist found that the bed of Kingman Lake was composed almost entirely of fecal matter, and warned that no one should swim in the lake due to the extensive pollution.